Hi, yes sandwiches are convenient, you could always try and get hold of some low carb bread, or consider other options, like taking some things from home to work, pack up lunch, you could do a tub of salad and have it with a frittata, or salad or veg with some hummous, tinned fish you only need to unzip that, yoghurt, the possibilities are endless there and dont have you send your bg soaring.
All the best
Karen